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Investigation of solid-phase ozonolysis reactions for use in a personal sampling method for ozone.
Blehm-KD; McCammon-CS Jr.; Tessari-JD; Aaronson-MJ
Am Ind Hyg Assoc J 1986 Jun; 47(6):331-338
To achieve a more accurate method of monitoring ozone (10028156) exposure among approximately 975,000 workers in 157 different occupations, three ozonolysis reactions were tested in the solid phase for reproducibility and quantitative yield of an aldehyde reaction product. Starting olefins were t-stilbene, 4,4'dimethoxystilbene and 1,2-di-(4-pyridyl)ethylene which respectively yielded benzaldehyde, p-anisaldehyde and pyridine-4- aldehyde on reaction with ozone. Starting olefins were coated on a variety of solid substrates, exposed to known ozone concentrations, and then analyzed for aldehydes. The ozonolysis reactions worked best on Florisil. None was stable in the solid phase, and aldehyde yields were unpredictable. Results obtained in the liquid phase could not be extrapolated to the solid phase. Several elements affected the reproducibility of aldehyde yields, including variability of olefin loading on the solid support, sample flow rate and sampling duration, varied ozone concentrations, time of sample elution and sample storage, and different elution solvents. Spontaneous oxidation of the olefins coated on solid supports was noted in bulk sorbents stored over time and during samples. The sorbents were not stable over time as large blank concentrations of the aldehyde occurred. The yields of aldehyde from sampling ozone in air, with corrections made for blank amounts, were much too large to be accounted for by ozone alone. Oxygen in the ozone sample was a major interferent, making the reaction a very poor predictor for ozone. The aldehyde formed on the sorbent was not stable in a flowing media. Attempts to trap the volatilized aldehydes with other solid traps were unsuccessful. The authors conclude that either more stable olefins must be found, or the olefin must be stabilized so that it will not react with oxygen if further research in this area is to be productive.
NIOSH-Author; NIOSH-Grant; NIOSH-Publication; Monitoring-systems; Air-monitoring; Air-samplers; Chemical-indicators; Industrial-hazards; Toxic-gases
Issue of Publication
American Industrial Hygiene Association Journal
Page last reviewed: September 13, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division